package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author HSJ
 * @since 2023-02-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {
    @Resource
    private UserServiceImpl userService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();
        // 查询用户
        records.forEach(blog -> {
            Long userId = blog.getUserId();
            User user = userService.getById(userId);
            blog.setName(user.getNickName());
            blog.setIcon(user.getIcon());
            isBlogLiked(blog);
        });
        return Result.ok(records);
    }

    @Override
    public Result queryById(Long id) {
        Blog blog = getById(id);
        if (blog == null) {
            return Result.fail("笔记不存在");
        }
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setIcon(user.getIcon());
        blog.setName(user.getNickName());
        //查询blog有没有被当前用户点过赞
        isBlogLiked(blog);
        return Result.ok(blog);
    }

    private void isBlogLiked(Blog blog) {
        //判断当前用户是否已经 点赞， 已经点赞给isLike赋值 true， 没有点赞 isLike=false
        UserDTO user = UserHolder.getUser();
        if(user ==null){
            //用户未登录
            return;
        }
        Long userId = user.getId();
        String key = RedisConstants.BLOG_LIKED_KEY + blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        blog.setIsLike(score != null);
    }

    @Override
    public Result likeBlog(Long id) {
        //判断当前用户是否已经 点赞， 已经点赞给isLike赋值 true， 没有点赞 isLike=false
        Long userId = UserHolder.getUser().getId();
        String key = RedisConstants.BLOG_LIKED_KEY + id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if (score == null) {
            //如果 未点赞，可以点赞
            //数据库+1
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            //保存到redis集合                      ZADD key value score          按照时间戳排序 ，越早越靠前
            if (isSuccess) {
                stringRedisTemplate.opsForZSet().add(key, userId.toString(),System.currentTimeMillis());
            }
        } else {
            //如果 已点赞，点赞数 -1
            boolean isSuccess = update().setSql("liked = liked-1").eq("id", id).update();
            if (isSuccess) {
                //把该记录 从redis的set里移除
                stringRedisTemplate.opsForZSet().remove(key,userId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result queryBlogLikes(Long id) {
        String key = RedisConstants.BLOG_LIKED_KEY+id;
           //查询 top5 的 点赞用户  zrange 0  4
        Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if( top5 ==null || top5.isEmpty()){
            return Result.ok(Collections.emptyList());
        }
        List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        String idsStr = StrUtil.join(",", ids);
        //如果使用mybatis默认的查询， select  from  where in(id1,id2) 结果不会按id照顺序查出，需要进行 order by id
        List<UserDTO> top5DTOs = userService.query().in("id",id).last("ORDER BY FIELD( id,"+idsStr+")").list()
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        return Result.ok(top5DTOs);
    }
}
